Piston



May 8, 1923. 1,454,762 A. {\IELSON PISTON Filed March 7. 1921 30agreeable noise in ay S, i923.

-NTED ADOLPH L. NELSON, F IN'DiANAPOLIS, INDIANA, ASSIGNOR OF ONE-THIRDTO S. CRAWFORD, OF INDIANAPOLIS, INDIANA.

PISTON.

Application filed March 7, 1921. Serial No. 450,189.

To all whom it nmp cdnoem:

Be it known that I, AnoLrH L. Nelson,

a citizen or the United States, residing at Indianapolis, in the countyof Marion and State of Indiana, have invented certain new combustionengines. In such engines a.

great deal of heatlis evolved in the cylinders, causingboth'cyhnders andistons, to

expand. With cast iron pistons t is not excessive and-they may fit thecylinders fairly close at all times. With pistons of hi hly expan'siblemetal, such as aluminum alfiiy, for example, much more clearance must beallowed, the expansion of the piston being materially greater than thatof the cylinder. Some of the larger pistons are water cooled in presentpractice, but most a of them are not and as the top of the pis ton issubjected to very hi h temperature in use, it is necessary that t is topand adjacent parts should be materially smaller than the cylinder toavoid scoring the cy1- inders and binding of the pistons in the cylinders. This results in excessive clearance when the engine is cool andcausesaflis piston slap. a

As the engine is heated, this noise'lesse'ns and finally disappears whenthe clearance of the piston in the cylinder has been sufli cientlyreduced. -.The object of my said invention is to pro-' vide a pistonconstruction wherein this piston slapping noise will be eliminated; alsoto rovide a construction that will obviate the co eakage of oil past thec linder head and consequent objections an' alsoto prevent the loss ofpower resulting from loose pistons, allas will be hereinafter more fullydescribed and claimed.

48 Referring to the accompanying drawings which are made a part hereofand on which similar reference characters indicate similar parts,

Figure -1 is a central section through'a so piston showing one form ofmy improved construction, I

Fi re 2, a view partly in elevation and part y in section at rightangles to the section of Figure 1. I y

the cylinder, known Figure 3, a view similar to Figure 1, showing amodified'form, and

Figure 4, a similar view showing a still further modified form.

The eneral form of the piston is the same in all 516 views onlydiffering in details as will be hereinafter more fully described.

The piston is provided with ahead 5, having grooves '6 for the packingrings, and a skirt 7. It will be understood that the normal diameter ofthe head 5-is slightly less than the largest-diameter of the skirt 7,providing a clearance between the head and the cylinder, to be filled ortaken 7 the piston packing rings as is usual.

difierende in diameter is, however, diificult' to show on the drawingsbecause it is so comparatively slight. As will vbe seen bycom aringFigures 1 and 2, the skirt 7 is pre er'ably of smaller diameter inthedirection of the hue of the wrist-pin than in a direction at rightangles with the wrist-pin,

so that the wrist-pin bea 11 may be formed in lugs which exten bothoutside and inside the normal line of the wall of the skirt as indicatedmost clearly in Fig- .ure 2.

Said skirt 'Z- is' partially separated from thehead by slots- 8. whichextend inwardly from diametrically opposite sides and parallel with theend face of the piston for adistance and then curve andextend' at rightangles to said face to a oint sube s ction shown in Figures 1 and 2 itwill be notedthat-these slots extend only slightly beyond the wrist-pin,while in the construction shown-in Figure-3 they extend for a.

considerable distance beyond the wrist-pin and in the construction shownin Figure 4 a less distance beyond the wrist-pin. Their length and widthmay be proportioned to is'to be used and the material of which thepiston is made and its construction in other particulars, the purposebeing 'in all cases to provide a skirt, the sides of which that areopposite the axial line 'of' the wrist-pin stantially on a line with orbeyon the outer dlgf of the wrist-pin bearing. In the con-, 7 t

suit. the conditions under which the piston the contraction andexpansion of the cyl- .been experienced. Said slots 8 separating themain portion of the skirt which bears against the c linder from thepiston head,

serve to ins ate said skirt from said head and guard the skirt againstthe excessive contraction and expansion that would result if the skirtat these points was directl connected with said head. Said slots 8 thusdivide the upper portions 9 of the bearing sides of the skirt from thepiston head, and as the lower or extreme outer portion of the skirt isbut slightly afiected by the heat from the piston head, a skirt 1sformed adapted to be substantially constant in its diameter. Theseportions 9 are braced by 'a bar 10 which in the form shown in Figures 1and 2 is integral therewith and extends at right angles with thewrist-pin and above said wrist-pin connecting the upper ends of saidportions 9 and holdin .them substantially rigid. Flanges an 21. may beformed around the edges of the slots 8 to stifien the parts and enablethe skirt to be made of thinner metal than would otherwise be required.A web or brace 22 may also extend from one side 0 he iston head to theother, preferabl joinln'g one wrist-pin I bearing 11 with t e other andserye to stiffen and strengthen the head and also provide fortransmission of heat through these reinforced metal parts as may berequired to secure the degree of expansion necessary to maintain auniform fit between the skirt and the cylinder.

In Figure 3, I show a construction similar to that shown in Figure 1,exce t that the piston head has a central depen ing lug 12 in which issecured the central portion of a cross brace 14, the ends of which aresecured in lugs in the upper ends of the separated portions 9 of. theskirt. By this means the said portions are held rigid with the center ofthe cylinder and the piston head is kept centrallfy located in res ct tothe side ortions 0 the piston, an' means is provided for transmittin theheat required to, secure the 88 81181011 necessary to maintain a uniformfit M. can the cylinder and piston.

Figure 4 shows a similar construction except the depending lug 15 andcross brace 16 are integral with the head and the separated portions 9of the skirt.

Having thus fully described my said in-. vention, what I claim as newand desire to secure by Letters Patent is:

1. A piston for internal combustion engines comprising a head, a skirt,the skirt having slits or openings extending from immediately beneaththe piston head inwardly and downwardly on each side of the wrist pinbearings to form tongues, a single brace connecting the top portions ofthe tongues, said tongues being unrestricted for expansion between thesaid upper brace and the connection of the tongue with the skirt of thepiston, substantially as set forth.

2. A piston comprising a. head and a skirt formed with openings extendintransversely thereinto from opposite sides and then toward the rear ofthe skirt alongside the wrist-pin bearings, and a rigid brace connectingthe upper ends of said separated portions, and also connected with arigid lug centrally located on the piston head, substantially as setforth.

3. Apiston comprising a head and a skirt with wrist-pin bearings, saidskirt being also formed with slots separating the head from the bearingsides of, the skirt at the upper end of said sides and an arched braceconnecting said separated portions, substantially as set forth.

4. A piston comprising a circular head and a skirt with wrist-pinbearings and formed of smaller diameter in line with.

said bearings than transversely thereof and with slots separating theupper ends of the "sides of the skirt opposite the axial line-of theWrist-pin from the head and a brace connecting said separated portionsand a this 22nd day of. February, A. D. nineteen hundred and twenty-one.

ADOLPH NELSON. a 5.1

Witnesses:

E. W. Bmnronn, M. L. Summ-

